When Mr Farage said there are many reasons, other than the EU, for peace on the Continent, Johnson added: “One of them is we are part of the EU and it has kept peace in Europe.”

Snap election 2017: The pictures politicians may not want you to see Sat, May 27, 2017

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Jeremy Corbyn during a visit to Hackney Marshes Football Pitches, to highlight Labour's manifesto commitment to ensure 5% of the Premier League's television rights income is diverted to the grassroots game, during a General Election campaign

An amused Mr Farage hit back, he said: “Are you saying without the EU the Germans would have invaded again?

“Are you really saying that?”

Johnson replied: “Because of the EU the Germans have been a real force for stability in Europe and an engine of growth.”